Bulb to water surface

[Holyreefer]

I have 3 400 watters over my 210
How far should i keep these reflectors with 400watts per bulb from the surface of the tank water hanging. The Hamilton Cozumel Sun Reflectors- Large (20x20)

Also to help me keep in mind i do still want to be able to access the tank for maintance etc...
I plan on keeping mainly SPS but also some lps acans, scolys, brain etc... so really a mixed reef tank

 

[mike_cmu04]

At least 8" but i would go 12" they put out tons of heat

 

[Holyreefer]

8 inchs ok...
Yeah i figured they were going to be very heat generating thats why i got the chiller on and am planning to only run the Halides 8 hours a day seeing they are the only source of light (No supplements) so i have to get the right bulbs and color of choose for myself.
Maybe ill even do 10 inches seeing thats the middle point between 8-12. I already know with the lights being that close my growth is going to be CRAZY!...Hopefully the heating issue of the tank its self wont become to much of a probleme